Hello, @antoniskaratzis,
There are 15 pre-built layouts for the single product page that you can easily import using Porto Studio on your site. These layouts are not limited to the pre-built demos and are specifically available for import in the single product template under Porto >> Template Builder.
Please see this screenshot for reference: https://pasteboard.co/id0N1HwpuD5k.png.
You can choose any layout from this selection and customize the content to fit your needs.
Best Regards,
PThemes Team.